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1.
Exp Appl Acarol ; 78(1): 133-147, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-31093859

RESUMEN

A new tick species of the genus Ornithodoros (Acari: Argasidae) was described from larvae collected on the toad Rhinella arenarum in a locality from Argentina belonging to the Monte Biogeographic Province. Ornithodoros montensis n. sp. was described based on morphological traits and sequences of the mitochondrial 16S rRNA gene. The diagnostic characters for this species are a combination of idiosoma oval, dorsal plate pyriform with posterior margin slightly concave, dorsal surface with 17 pairs of setae (7 anterolateral, 4 to 5 central and 5 to 6 posterolateral), ventral surface with 6 pairs of setae and 1 pair on anal valves, three pairs of sternal setae, postcoxal setae absent, and hypostome pointed apically with dental formula 3/3 in the anterior half and 2/2 posteriorly almost to base. Phylogenetic analysis of 16S rDNA sequences and a principal component analysis based on morphometric characters provided additional support to the description of O. montensis as an independent lineage within the genus Ornithodoros. Larvae of O. montensis are phylogenetically closely related to O. puertoricensis, O. rioplatensis, O. talaje s.s., O. guaporensis, O. hasei and O. atacamensis, all of them belonging to the "O. talaje group".


Asunto(s)
Bufonidae/parasitología , Interacciones Huésped-Parásitos , Ornithodoros/clasificación , Animales , Argentina , Larva/anatomía & histología , Larva/clasificación , Larva/genética , Ornithodoros/anatomía & histología , Ornithodoros/genética , Ornithodoros/crecimiento & desarrollo , ARN Ribosómico 16S/análisis
2.
Ecotoxicol Environ Saf ; 177: 32-38, 2019 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-30959310

RESUMEN

Morphological abnormalities in amphibians may be attributed to contaminants, ultraviolet radiation and trematode parasites, or a synergistic effect between them. In the present study, morphological abnormalities in Rhinella arenarum adults from natural and artificial fluoride-rich environments were identified and evaluated. Three sites were sampled in central Argentina: Los Vallecitos stream (LF-LV), Los Cerros Negros stream (MF-CN), and Decantation ponds (HF-DP), with low (0.33 mg/L), middle (2.03 mg/L) and high (14.0 mg/L) fluoride levels respectively; the latter site is associated with a fluoride mine. Abnormal individuals were photographed and then standard radiographs were taken. Abnormality frequencies and relative percentage of abnormal individuals were calculated for each site. In addition, skeletochronology was used to estimate toad's age. Five abnormality types were identified: syndactyly, ectrodactyly, polydactyly, microphthalmia and ectromelia. Percentages of abnormal individuals per site were: LF-LV = 4%, MF-CN = 21.2% and HF-DP = 6.4%. The MF-CN and HF-DP populations had morphological abnormality frequencies that exceeded the reference value (5%) reported in the literature. The average age did not differ between sites. The results of this study indicate that there is an association between frequency of morphological abnormalities and high fluoride levels.


Asunto(s)
Bufonidae/anomalías , Contaminantes Ambientales/toxicidad , Fluoruros/toxicidad , Rayos Ultravioleta , Animales , Argentina , Bufonidae/parasitología , Femenino , Estanques , Ríos/química
3.
Acta Parasitol ; 64(1): 171-175, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30645738

RESUMEN

AIMS: The purpose of this article is to describe a new species of Rhabdias Stiles and Hassall, 1905 from West Bengal, India. Rhabdias bengalensis sp. nov. (Nematoda, Rhabdiasidae) recovered from the lungs of Asian common toad, Duttaphrynus melanostictus (Schneider, 1899), collected from Illambazar town, Birbhum district of West Bengal, India. METHODS: The collected nematode specimens were clean by shaking them in 0.67% NaCl solution and were killed and fixed in steaming 70% alcohol; lactophenol was used as a mounting medium for light microscopic examination. The lactophenol treated specimens after examination were directly transferred to 70% alcohol and could be stored satisfactorily. RESULTS: The new species is named as, R. bengalensis sp. nov. (Nematoda, Rhabdiasidae), in reference to its locality of collection, West Bengal, India. The worms are small [(2.84-2.96 mm) in length], anterior end somewhat truncated and posterior end tapering. R. bengalensis sp. nov. is characterised by rounded mouth without lips, inflated cuticle, cup-shaped buccal capsule, pre-equatorial vulva and a conical tail. CONCLUSION: The present nematodes, thus, appear to be new in the field of science and name R. bengalensis sp. nov. is proposed for them. R. bengalensis sp. nov. represents 17th species described from oriental region and the 10th species from India.


Asunto(s)
Bufonidae/parasitología , Enfermedades Pulmonares Parasitarias/veterinaria , Infecciones por Rhabditida/veterinaria , Rabdítidos/clasificación , Rabdítidos/aislamiento & purificación , Animales , India , Pulmón/parasitología , Enfermedades Pulmonares Parasitarias/parasitología , Microscopía , Parasitología/métodos , Rabdítidos/anatomía & histología , Infecciones por Rhabditida/parasitología
4.
Med Vet Entomol ; 33(1): 131-139, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30091469

RESUMEN

The blow fly genus Lucilia is composed largely of saprophages and facultative myasis agents, including the economically important species Lucilia cuprina (Wiedemann) (Diptera: Calliphoridae) and Lucilia sericata (Meigen). Only one species is generally recognized as an obligate agent of myiasis, Lucilia bufonivora Moniez, and this is an obligate parasite of toads. Lucilia silvarum (Meigen), a sister species, behaves mainly as a carrion breeder; however, it has also been reported as a facultative parasite of amphibians. Morphologically, these species are almost identical, and historically this has led to misidentification, taxonomic ambiguity and a paucity of studies of L. bufonivora. In this study, dipterous larvae were analysed from toad myiasis cases from the U.K., The Netherlands and Switzerland, together with adult specimens of fly species implicated in amphibian parasitism: L. bufonivora, L. silvarum and Lucilia elongata Shannon (from North America). Partial sequences of two genes, cox1 and ef1α, were amplified. Seven additional blow fly species were analysed as outgroups. Bayesian inference trees of cox1, ef1α and a combined-gene dataset were constructed. All larvae isolated from toads were identified as L. bufonivora and no specimens of L. silvarum were implicated in amphibian myiasis. This study confirms L. silvarum and L. bufonivora as distinct sister species and provides unambiguous molecular identification of L. bufonivora.


Asunto(s)
Bufonidae/parasitología , Dípteros/clasificación , Dípteros/genética , Interacciones Huésped-Parásitos , Proteínas de Insectos/análisis , Animales , Evolución Biológica , Dípteros/fisiología , Complejo IV de Transporte de Electrones/análisis , Miasis/parasitología , Miasis/veterinaria , Factor 1 de Elongación Peptídica/análisis , Filogenia , Análisis de Secuencia de ADN/veterinaria
5.
Acta Parasitol ; 63(4): 750-758, 2018 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-30367751

RESUMEN

Rhabdias garhwalensis sp. nov. from the lungs of Duttaphrynus himalayanus (Günther, 1864) collected in Kimoi Tehsil, district Tehri Garhwal (Uttarakhand), India is described and illustrated. Rhabdias garhwalensis sp. nov. represents the 15th species described from the Oriental zoogeographical zone and the 9th species from India. The new species is differentiated from the closely related Oriental species in having 6 lips, cup-shaped buccal cavity with muscular striations in the posterior region and smaller esophagus to body length ratio. In addition to the new species, a second species, Cosmocercoides bufonis Karve, 1944, was found in the large intestine of D. himalayanus.


Asunto(s)
Bufonidae/parasitología , Infecciones por Strongylida/veterinaria , Strongyloidea/clasificación , Animales , Femenino , India/epidemiología , Intestino Grueso/parasitología , Pulmón/parasitología , Masculino , Prevalencia , Infecciones por Strongylida/epidemiología , Infecciones por Strongylida/parasitología , Strongyloidea/anatomía & histología
6.
Exp Appl Acarol ; 75(4): 399-407, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-30088214

RESUMEN

Amphibians and Squamata reptiles belonging to a zoological collection were screened for ectoparasites, which were removed from the hosts and identified using morphological keys. Descriptive statistics and analysis of the association between the parasite and host characteristics (taxonomic group, capture location and habitat) were done. Among the 1256 animals examined (319 amphibians and 937 reptiles), 86 individuals were parasitized, corresponding to a frequency of 6.9% (6.6% reptiles and 7.5% amphibians). Ticks in the adult and nymph stages were identified to the species level; all of them belonged to the species Amblyomma dissimile. The larvae were identified to the genus level and were all Amblyomma sp. In total 69 larvae, 28 nymphs and eight adults were found. The most parasitized species was the frog Rhinella major: 24 parasitized animals of 65 examined (36.9%). There was a difference (P < 0.001) between parasitism by ticks of the genus Amblyomma with regard to the habitat of capture of the parasitized animal, with a higher parasitism rate in hosts that inhabited open areas as compared to animals ensconced in forest areas and edges of forests. New tick-host associations are given.


Asunto(s)
Ixodidae/clasificación , Reptiles/parasitología , Anfibios/parasitología , Animales , Biodiversidad , Brasil , Bufonidae/parasitología , Ecosistema , Femenino , Interacciones Huésped-Parásitos , Ixodidae/anatomía & histología , Ixodidae/crecimiento & desarrollo , Larva/clasificación , Lagartos/parasitología , Masculino , Infestaciones por Garrapatas/veterinaria
7.
Ticks Tick Borne Dis ; 9(5): 1350-1353, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29934040

RESUMEN

Amblyomma rotundatum is an ixodid tick strictly associated with cold-blooded animals, among them the toad Rhinella jimi. This work aimed to evaluate the seasonal dynamics of larvae, nymphs, and adults of A. rotundatum parasitizing R. jimi in an area within the semi-arid Caatinga Biome of northeastern Brazil. Monthly sampling from February 2014 to January 2016 resulted in a total of 592 R. jimi toads captured and inspected for infestation by ticks, which were counted and identified. After the procedure, the toads were released with their ticks at the same capture site. During the study period, a total of 658 A. rotundatum were counted, comprising 497 larvae, 110 nymphs, and 51 females. The two-year mean abundances of larvae, nymphs, and adults were 0.84, 0.19, and 0.09, respectively. The two-year mean infestation intensities of larvae, nymphs, and adults were 3.65, 1.45, and 1.34, respectively. Comparing the monthly values of prevalence, mean abundance, and mean infestation intensity of A. rotundatum life stages, differences were observed between the first and second year of study; however, with no clear seasonal pattern.


Asunto(s)
Bufonidae/parasitología , Ixodidae/fisiología , Estaciones del Año , Animales , Brasil/epidemiología , Clima Desértico , Femenino , Larva/fisiología , Ninfa/fisiología , Dinámica Poblacional , Infestaciones por Garrapatas/epidemiología , Garrapatas/fisiología
8.
Rev Bras Parasitol Vet ; 27(3): 390-395, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29846455

RESUMEN

Although a group of soft ticks (Argasidae) associated with amphibians was recently discovered in Brazilian rainforests, parasitism by these ticks on cold-blooded animals remains less common than on mammal and bird species. In this study, we identified ticks that were collected from toads that had been caught in December 2016 and January 2017, at Itinguçú waterfall (22°54'05" S; 43°53'30" W) in the municipality of Itaguaí, state of Rio de Janeiro. Tick specimens were identified using a morphological and molecular approach. In total, twelve larvae of Ornithodoros ticks were collected from three individuals of Rhinella ornata and were identified as Ornithodoros faccinii. Our results include a longer 16S rRNA mitochondrial sequence for O. faccinii that supports its phylogenetic relatedness to Ornithodoros saraivai, and we report this tick species parasitizing Rhinella toads for the first time in Brazil.


Asunto(s)
Bufonidae/parasitología , Ornithodoros/genética , Infestaciones por Garrapatas/parasitología , Animales , Brasil , Ornithodoros/anatomía & histología , Ornithodoros/clasificación , Filogenia , ARN Ribosómico 16S
9.
Parasitol Res ; 117(6): 1857-1864, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29680942

RESUMEN

A new cosmocercid species, Cosmocercoides qingtianensis sp. n., collected from the intestine of the Asiatic toad Bufo gargarizans Cantor (Amphibia: Anura) is described using integrated approaches, including light and scanning electron microscopy, and sequencing and analyzing the ribosomal [small ribosomal DNA (18S) and internal transcribed spacer (ITS)] and mitochondrial [cytochrome c oxidase subunit 1 (cox1)] target regions, respectively. The new species can be distinguished from its congeners by the combination of the following morphological characters, including the large body size, the presence of lateral alae and somatic papillae in both sexes, the length of spicules, the particular morphology and length of gubernaculum, the number, arrangement and morphology of caudal rosettes, the presence of large medioventral precloacal papilla and the long tail. Our molecular analysis revealed the level of intraspecific genetic variation of C. qingtianensis sp. n. distinctly lower than that of the interspecific genetic variation in the ITS and cox1 regions. However, there are some overlaps in the range of intra- and interspecific 18S sequence divergence between the new species and some closely related species. The results of molecular analysis supported the validity of the new species based on the morphological observations. The 18S, ITS, and cox1 regions of C. pulcher collected from Bufo japonicus formosus in Japan were also sequenced and analyzed. The results showed a low level of intraspecific genetic variation in 18S and ITS regions (0-0.12% and 0-0.23% nucleotide differences, respectively), but a relatively high level of intraspecific genetic variation in cox1 region (0.78-4.69% nucleotide differences). In addition, it seems more powerful and practical to use the cox1 region as a genetic marker for the accurate identification and differentiation of species of Cosmocercoides than the 18S and ITS regions, especially for the closely related species.


Asunto(s)
Ascarídidos/clasificación , Ascarídidos/genética , Bufonidae/parasitología , Animales , Ascarídidos/aislamiento & purificación , ADN Intergénico/genética , ADN Ribosómico/genética , Complejo IV de Transporte de Electrones/genética , Femenino , Variación Genética/genética , Intestinos/parasitología , Japón , Masculino , Microscopía Electrónica de Rastreo , ARN Ribosómico 18S/genética
10.
Syst Parasitol ; 95(5): 447-454, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29637423

RESUMEN

Everted cystacanths of Sphaerirostris lanceoides (Petrochenko, 1949) Golvan 1956 are reported from the Asiatic toad Bufo gargarizans Cantor (Amphibia: Anura) for the first time. The prevalence was 1.96% and the intensity ranged between 1.0-3.0 acanthocephalans. SEM observations revealed the morphology of the gonopore and the presence of a flat, bare region on the apical part of the proboscis. Moreover, S. lanceoides was characterised using molecular approaches by sequencing the ribosomal ITS1-5.8S-ITS2 region and the mitochondrial cox1 gene. The resulting ITS sequences were identical and the cox1 sequences showed a divergence of 0-0.75%. Sphaerirostris lanceoides is the first species of the genus for which the ITS1-5.8S-ITS2 and cox1 loci have been sequenced to aid species identification.


Asunto(s)
Acantocéfalos/clasificación , Bufonidae/parasitología , Helmintiasis Animal/parasitología , Acantocéfalos/genética , Acantocéfalos/ultraestructura , Animales , China , ADN Ribosómico/genética , Complejo IV de Transporte de Electrones/genética , Especificidad de la Especie
11.
Acta Parasitol ; 63(1): 175-183, 2018 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-29351060

RESUMEN

Rhabdias stomatica sp. nov. from the lungs of Duttaphrynus stomaticus (Lutken, 1864) from Dehradun, Uttarakhand, India is described and illustrated. Rhabdias stomatica sp. nov. is the 16th species described from the Oriental biogeographical region and the 8th species from India. The new species is differentiated from the closely related Oriental species in having 4 weakly developed lips, a trapezoidal shaped buccal cavity, different position of nerve ring and in the esophagus/body length ratio. In addition, to the new species found in the lungs, mature specimens of Aplectana macintoshii (Stewart, 1914) Travassos, 1931 and larvae representing two unidentified species of nematode were found in the large intestine of the D. stomaticus.


Asunto(s)
Bufonidae/parasitología , Pulmón/parasitología , Tylenchida/clasificación , Tylenchida/aislamiento & purificación , Estructuras Animales/anatomía & histología , Animales , Ascarídidos/clasificación , Ascarídidos/aislamiento & purificación , Biometría , India , Microscopía , Tylenchida/anatomía & histología
12.
Parasitology ; 144(6): 817-822, 2017 05.
Artículo en Inglés | MEDLINE | ID: mdl-28073381

RESUMEN

Across host-parasite systems, there is evidence that pesticide exposure increases parasite loads and mortality following infection. However, whether these effects are driven by reductions in host resistance to infection or slower rates of parasite clearance is often unclear. Using controlled laboratory experiments, we examined the ability of larval northern leopard frogs (Lithobates pipiens) and American toads (Anaxyrus americanus) to resist and clear trematode (Echinoparyphium sp.) infections following exposure to the insecticide carbaryl. Northern leopard frogs exposed to 1 mg L-1 of carbaryl had 61% higher parasite loads compared with unexposed individuals, while there was no immediate effect of carbaryl on parasite encystment in American toads. However, when tadpoles were exposed to carbaryl and moved to freshwater for 14 days before the parasite challenge, we recovered 37 and 63% more parasites from carbaryl-exposed northern leopard frogs and American toads, respectively, compared with the control. No effects on clearance were found for either species. Collectively, our results suggest that pesticide exposure can reduce the ability of amphibians to resist parasite infections and that these effects can persist weeks following exposure. It is critical for researchers to incorporate species interactions into toxicity studies to improve our understanding of how contaminants affect ecological communities.


Asunto(s)
Bufonidae/parasitología , Carbaril/toxicidad , Echinostomatidae/fisiología , Insecticidas/toxicidad , Rana pipiens/parasitología , Infecciones por Trematodos/veterinaria , Análisis de Varianza , Animales , Bufonidae/inmunología , Resistencia a la Enfermedad/efectos de los fármacos , Echinostomatidae/efectos de los fármacos , Indiana , Larva/efectos de los fármacos , Larva/inmunología , Larva/parasitología , Estanques , Rana pipiens/inmunología , Caracoles/parasitología , Infecciones por Trematodos/inmunología
13.
Ecohealth ; 14(Suppl 1): 144-155, 2017 03.
Artículo en Inglés | MEDLINE | ID: mdl-27056609

RESUMEN

Decision-analytic models provide forecasts of how systems of interest will respond to management. These models can be parameterized using empirical data, but sometimes require information elicited from experts. When evaluating the effects of disease in species translocation programs, expert judgment is likely to play a role because complete empirical information will rarely be available. We illustrate development of a decision-analytic model built to inform decision-making regarding translocations and other management actions for the boreal toad (Anaxyrus boreas boreas), a species with declines linked to chytridiomycosis caused by Batrachochytrium dendrobatidis (Bd). Using the model, we explored the management implications of major uncertainties in this system, including whether there is a genetic basis for resistance to pathogenic infection by Bd, how translocation can best be implemented, and the effectiveness of efforts to reduce the spread of Bd. Our modeling exercise suggested that while selection for resistance to pathogenic infection by Bd could increase numbers of sites occupied by toads, and translocations could increase the rate of toad recovery, efforts to reduce the spread of Bd may have little effect. We emphasize the need to continue developing and parameterizing models necessary to assess management actions for combating chytridiomycosis-associated declines.


Asunto(s)
Bufonidae/parasitología , Quitridiomicetos/patogenicidad , Micosis/veterinaria , Animales , Dinámica Poblacional
14.
Acta Parasitol ; 61(3): 567-75, 2016 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-27447222

RESUMEN

Oswaldocruzia chambrieri Ben Slimane et Durette-Desset, 1993 is redescribed from specimens collected from the small intestine of the South American common toad, Rhinella margaritifera, from Caxiuanã National Forest in Pará, Brazil, using light and scanning microscopy and molecular analysis of Cytochrome Oxidase I (COI) - coding regions of DNA. The discovered nematodes are characterized by a type III caudal bursa with two papillae, rays 4 with a median groove, and spicules divided into a blade, a shoe and a fork. Cervical alae are absent, the cephalic vesicle is divided into two portions, and the synlophe has low ridges without chitinous supports. The present study establishes the Caxiuanã National Forest as a new location for O. chambrieri, which had previously been reported as a parasite of R. margaritifera in Ecuador, uses light microscopy and scanning electron microscopy (SEM) to identify new morphological characters of the species and represents the second molecular sequence deposited for the Oswaldocruzia genus.


Asunto(s)
Bufonidae/parasitología , Molineoidae/crecimiento & desarrollo , Molineoidae/aislamiento & purificación , Infecciones por Strongylida/veterinaria , Animales , Brasil , Bosques , Intestino Delgado/parasitología , Molineoidae/genética , Infecciones por Strongylida/parasitología
15.
Acta Parasitol ; 60(4): 784-90, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26408605

RESUMEN

This is the first record of the nematode parasite Schulzia travassosi (Trichostrongylina, Molineidae) in two Argentinean amphibians, Leptodactylus bufonius and Rhinella major, collected in two localities of the Chaco region, Las Lomitas (Formosa Province) and Taco Pozo (Chaco Province). The species was observed using light and scanning electron microscopy (SEM) and compared with previous studies of Paraguayan specimens. Regarding metric characters, the measurements found in Argentinean specimens generally did not differ from those of Paraguayan specimens; some differences were observed in the total length of males and females (some longer and some shorter than Paraguayan specimens), length of the oesophagus (in almost all specimens shorter than in Paraguayan ones) and position of the vulva (nearer to posterior end in Argentinean specimens). The branches and sphincter of ovejector are slightly longer than in Paraguayan female specimens. In males, ray 4 is almost the same length as rays 2, 3 and 5, 6. Cephalic end, cephalic vesicle, synlophe and vulvar depression were viewed under SEM. Schulzia melanostictusi Chopra, Shing and Kumar, 1986 is reassigned as Oswaldocruzia melanostictusi (Chopra, Shing and Kumar, 1986) nov. comb.


Asunto(s)
Anuros/parasitología , Bufonidae/parasitología , Nematodos/clasificación , Nematodos/aislamiento & purificación , Infecciones por Nematodos/veterinaria , Estructuras Animales/anatomía & histología , Animales , Argentina , Femenino , Masculino , Microscopía , Nematodos/anatomía & histología , Infecciones por Nematodos/parasitología
16.
Parasitol Res ; 114(12): 4685-92, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26346456

RESUMEN

Currently, little information is available on helminth community structure in tadpoles, the ephemeral, feeding, non-reproductive larva stages of anurans. We examined the helminth community structure in tadpoles of northern leopard frogs, Rana pipiens, and Woodhouse's toads, Bufo woodhousii, from a first-order stream in Western Nebraska. Specifically, we were interested in how species-specific difference in size, time to metamorphosis, and habitat partitioning among larval anurans affect their helminth community structure. From June-July 2009, we collected 30 tadpoles of northern leopard frogs, R. pipiens, and 50 tadpoles of Woodhouse's toads, B. woodhousii, from Cedar Creek, Keith County, NE, USA. The compound helminth community was dominated by trematode metacercarial stages (echinostomatids and plagiorchids) and the nematode Gyrinicola batrachiensis with only a single non-gravid adult trematode, Gorgoderina attenuata, present in low numbers. The helminth component communities were depauperate and isolationist in nature, with a maximum of four helminth species/types per component community. Although no species-specific helminth infections were observed, clear differences were found in overall abundance of nematode versus trematode infections among tadpoles of these two anuran species. The component community of tadpoles of R. pipiens was dominated by nematodes, whereas the component community of tadpoles of B. woodhousii was dominated by trematodes. Although differences in tadpole susceptibility of these two anuran species could not be ruled out, differences in the reproductive strategy of G. batrachiensis in tadpoles of R. pipiens and B. woodhousii and anuran species-specific habitats partitioning among tadpoles of these two anuran species were important factors in structuring their helminth communities. Our study indicates that time to metamorphosis (older tadpoles) play a significant role in structuring helminth communities of tadpoles within species at the infracommunity level with older tadpoles having higher helminth species richness and/or abundances. However, species-specific differences in anuran tadpole habitat partitioning outweighed the effects of differences in time to metamorphosis at the component community level. Finally, our study is the first to report deformities in hind limb development in a tadpole from Nebraska. Of the 30 northern leopard frog tadpoles collected, a single individual contained an extra hind limb and was infected with two plagiorchid metacercariae located in the musculature above the hind limbs.


Asunto(s)
Bufonidae/parasitología , Helmintiasis Animal/parasitología , Helmintos/aislamiento & purificación , Rana pipiens/parasitología , Animales , Femenino , Helmintos/clasificación , Helmintos/genética , Helmintos/fisiología , Larva/parasitología , Masculino , Nebraska , Rana pipiens/crecimiento & desarrollo
17.
Parasitol Res ; 114(11): 3989-97, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26266882

RESUMEN

The phylum Myxozoa comprises more than 2180 species, almost all of which are considered to be obligate parasites of aquatic fishes and amphibians. They are dangerous pathogens responsible for severe economic losses. From March to September 2014, 40 adult male Bufo regularis (Bufonidae) captured from different areas at Giza province, Egypt, were surveyed for myxosporean parasitic infection. Of these, 22 (55%) were infected by histozoic plasmodia, which produced spores after rupture belonging to Myxosporidia. The present investigation introduced a new data for the recorded parasite observed by light and transmission electron microscopy. The infection was diagnosed as large clusters of macroscopic plasmodia embedded in the testicular tissue causing distortion at the site of infection. The host reaction was manifested by the encapsulation of the plasmodia with a thick layer of connective tissue. Plasmodia were whitish in color, elliptical to ovoid in shape measuring 0.54 ± 0.2 (0.34-0.63) mm in diameter. The spores were subspherical, reaching 7.1 ± 0.2 (6.2-8.4) µm in length and 6.3 ± 0.2 (5.8-7.0) µm in width with two equal-sized polar capsules regularly arranged at the anterior pole of each spore. They were 3.4 ± 0.2 (3.0-4.2) µm in length and 1.9 ± 0.2 (1.6-2.4) in width with 6-8 turns of polar filaments. Ultrastructural analysis showed that the plasmodia were surrounded by a plasma membrane with numerous projections and pinocytotic channels extended toward the host cell. The generative cells and the different developmental stages were arranged at the periphery of the plasmodia while immature and mature spores were centrally arranged. Sporogenesis, capsulogenesis, valvogenesis, and spore maturation of the present parasite were also described.


Asunto(s)
Bufonidae/parasitología , Myxobolus/ultraestructura , Enfermedades Parasitarias en Animales/parasitología , Animales , Egipto , Masculino , Microscopía Electrónica de Transmisión/veterinaria , Esporas/ultraestructura
18.
J Parasitol ; 101(6): 658-65, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26301445

RESUMEN

Complex life cycles are a hallmark characteristic of many parasites; however, little is known about the process by which life cycles become more complex through the addition of hosts. Paratenic hosts are present in the life cycles of several phylogenetically distinct groups of helminths; this suggests that they may play a key role during this process. This study examined the development of metacercariae of Halipegus eccentricus within intermediate microcrustacean and odonate paratenic hosts. Then a comparative approach was used to evaluate how life history traits of H. eccentricus within the anuran definitive hosts differ between metacercariae of the same age that developed within an intermediate ostracod host or a paratenic odonate host. The results of this study indicate that metacercariae of H. eccentricus do not grow at the same rate in different intermediate hosts, and significant differences exist in growth within intermediate and paratenic hosts. Individuals from odonate paratenic hosts always had larger bodies and suckers than those of metacercariae of the same age that develop within microcrustacean intermediate hosts. Furthermore, metacercariae from odonates were more successful in establishing and migrating in definitive anuran hosts. Last, individuals from paratenic hosts began reproducing earlier within anuran definitive hosts than age-matched worms that develop within the intermediate hosts. Collectively these results suggest that the variation in body and sucker sizes within odonate and microcrustacean hosts may carry over to the definitive host and in the case of H. eccentricus using the paratenic host increases transmission and alters other life history traits within definitive hosts. These results indicate that using a paratenic host can affect the success of parasites in subsequent hosts, and therefore these hosts may provide benefits other than just increasing transmission by bridging an ecological gap.


Asunto(s)
Bufonidae/parasitología , Estadios del Ciclo de Vida/fisiología , Odonata/parasitología , Rana catesbeiana/parasitología , Trematodos/crecimiento & desarrollo , Infecciones por Trematodos/veterinaria , Animales , Crustáceos , Prevalencia , Caracoles , Factores de Tiempo , Infecciones por Trematodos/epidemiología , Infecciones por Trematodos/parasitología , Infecciones por Trematodos/transmisión
19.
Pesqui. vet. bras ; 35(6): 579-582, June 2015. graf
Artículo en Inglés | LILACS | ID: lil-766187

RESUMEN

We sampled ticks from specimens of the rococo toad Rhinella schneideriby flannel dragging on two Islands located in the São Francisco River near the Três Marias hydroelectric dam, southeastern Brazil. A total of 120 toads was examined, of which 63 (52.5%) were parasitized only by Amblyomma rotundatumtotaling 96 larvae, 163 nymphs and 134 females. The burden of parasitism ranged from one to 43 ticks, with a mean intensity of infestation of 6.2±5.5 ticks per host. The tick A. rotundatumexhibited highly aggregated distribution. Peak abundance of larvae and nymphs occurred in the dry season (May to September), whereas peak abundance of females occurred in the wet season (October to April). We collected most ticks near the head and hind limbs of R. schneideri. The finding of two engorged A. rotundatumnymphs in the same resting places of two toads and the absence of this species in the dragged areas suggest a nidicolous behavior at the studied site.


Sapos da espécie Rhinella schneideri foram capturados e examinados para coleta das fases parasitárias, assim como arrasto de flanela para coleta das fases de vida livres de carrapatos em duas ilhas localizadas no rio São Francisco , próximas à represa Três Marias, região sudeste do Brasil. No total, 120 indivíduos foram examinados, dos quais 63 (52,5%) estavam parasitados por Amblyomma rotundatum totalizando 96 larvas, 163 ninfas e 134 fêmeas. A abundância do parasitismo variou de 1 a 43 carrapatos, com uma intensidade média de infestação de 6,2±5,5 carrapatos/hospedeiro. A infestação por A. rotundatumapresentou uma distribuição altamente agregada. O pico de abundância de larvas e ninfas ocorreu na estação seca (maio a setembro), enquanto o pico de abundância de fêmeas ocorreu na estação chuvosa (outubro a abril). A maioria dos carrapatos foi coletada na região da cabeça e membros posteriores. A presença de duas ninfas ingurgitadas de A. rotundatum nos mesmos lugares de descanso de dois sapos e a ausência desta espécie na coleta por arrasto de flanela sugere um comportamento nidicola no local estudado.


Asunto(s)
Animales , Bufonidae/parasitología , Interacciones Huésped-Parásitos , Infestaciones por Garrapatas/veterinaria , Carga de Parásitos/veterinaria , Enfermedades Parasitarias/parasitología , Hemorragia/veterinaria , Pérdida de Peso
20.
Dis Aquat Organ ; 113(2): 157-62, 2015 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-25751858

RESUMEN

As part of a state-wide multispecies survey of amphibian diseases, sampling was conducted at Archbold Biological Station, Venus, Florida, USA, on 15 April 2011. Gross examination of southern toad (Anaxyrus terrestris) larvae was unremarkable, but infections by a mesomycetozoean-like organism were observed in longitudinally sectioned routine haematoxylin and eosin-stained histologic slides. In 100% of the sectioned specimens examined (n = 5), a high density of the organism, representing several developmental stages, was found in the central nervous system, mainly in the spinal cord, brain, retina and optic nerve. No host inflammatory responses were found to be associated with the parasitic infection. Free, mature schizonts were occasionally found in the gill chamber and, more commonly, in the dorsal roof area. No organisms were found in other organs examined histologically, i.e. liver, kidney, heart, alimentary tract, exocrine pancreas and skeletal muscles. Presumptive mesomycetozoean ichthyophonids in anurans are usually reported to be pathogenic, especially affecting skeletal muscle tissue and causing death. To our knowledge, this is the first report of a similar organism infecting primarily the central nervous system in an amphibian.


Asunto(s)
Bufonidae/parasitología , Infecciones por Mesomycetozoea/epidemiología , Mesomycetozoea/aislamiento & purificación , Animales , Florida/epidemiología , Larva/parasitología
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